1. Field
The following description relates to transmission in a multiple-input multiple-output (MIMO) antenna system. More particularly, the description relates to an apparatus and method of transmission of dynamic feedback channel information in a MIMO system.
2. Description of Related Art
A multiple input multiple output (MIMO) antenna system is a system where a plurality of antennas are located in a transmitter and each antenna independently transmits information to a receiver. Such systems are referred to as a MIMO system or a space division multiplexing (SDM) system. The MIMO antenna system is a system which utilizes a spatial area to enable high speed data transmission in limited frequency environments. According to research results to date, it is known that a channel capacity of the MIMO system increases proportionally to an increase in a number of transmission antennas and receiving antennas in the system.
A MIMO system having multiple users requires scheduling that enables multiple users to simultaneously communicate and is highly complex because each user's quality of service (QoS) requirements are considered. Recently, research regarding scheduling for multiple users, optimization for transmission/reception, and a feedback signal was conducted in the field of the MIMO systems.
An example of a conventional feedback scheme in the MIMO system is a method which notifies signal to interference and noise ratio (SINR) of each stream that can be received in a receiver. This method, however, can be considered ineffective because it wastes wireless resources. An example of another conventional method is a partial feedback method. In the partial feedback method, as a size of a code book is increased, more accurate channel state information may be fed back. This method is not desirable, however, because the feedback information is increased.